Unity Reflect Compile Error CS1069

Does anybody know how to fix the following error? The following shows Unity Editor version and Reflect package version:

Unity Editor Pro version: 2019.4.4f1.
Unity Reflect Package version: 2.0.1

When I went through the following Unity Learn after installing the latest Reflect package, the following error popped up and couldn't figure out how to fix this?
Unity Learn: https://learn.unity.com/tutorial/im...50bcedbc2a0c58023576#5e6fa65eedbc2a07115a5848

My frustration with the Unity Reflect and Unity Editor is nothing works. How will this fix? It's really hard to get hold of any tech support team, even my team tries to overcome the challenges. If anybody helps, it will be really appreciated